The Perseus bridge hologram compiled into existence before them. They entered.

She activated the master interface. “I shall endeavor to keep that in mind.”

Keeping a side scan on the fluctuating molecular image of Voyager, while simultaneously working on a previously unconceived subspace field algorithm, Vexa made her deductions: “There must be some kind of subspace interference with the computer network, given what's happening to Voyager – interference which is possibly even having a neurochemical effect on the crew.”

Grif looked up from the ops station. “How do you know it's neurochemical?”

“I do not. However when you exposed the intruder, you described an altered sense perception. It is logical to infer it was possibly some kind of defense mechanism the intruder employed. It would also explain the intruder's lack of physical interface with the computer system. However a subspace analysis would confirm or deny this effect. Unfortunately I still have no access to sensors.”

“Subspace telepathic computing? Is that even possible?”

“It is – untheorized.” She exhaled, erased her entire algorithm, and, with a little too much force, reset the interface. “Therefore countermeasures must also defy established physical probabilities.” She pulled up the security communications interface.

“You mean a shot in the dark. Doesn't sound very logical?”

She accessed the emergency command parameters. “The definition of an undisciplined mind, that cannot perceive the problem in terms of statistical probability.”

After a minute, Grif pounded his station. “No, it's not working. I still can't access security commands. So much for your theory.”

“So much for the hypothesis. The theory, however, may still be sound.” Vexa had a new idea; she pulled up the index of the quantum drive diagnostic systems.

Grif found the visual uplink of the bridge. “There she is.” Vexa's progressive molecular imaging scans of the bridge cast the intruder in a crisp image. The intruder remained cross-legged, spine erect in the command chair, “communing”, as Vexa had put it, with various bridge interfaces, which for the moment appeared to be in some kind of hyper-speed mode. He zeroed in on the intruder. She appeared to be a humanoid female. Her entire body, she now saw, reflected a rough, pearlescent texture that reminded Vexa of Earth coral, or shells. Her whitish hue did not glow continuously, but seemed to pulse softly at random intervals. Her hair – which was not hair – swept back over her cranium and hung in articulated fronds to her neck, again, like small interlocking white seashells. Her irises rippled the color spectrum. Her hands and feet were bare and turned upward. Vexa could not say for certain whether the intruder wore her articulated coverings, or if they were somehow part of her.

But she respirated. Subspace or not, she was at least in part, a creature of atmosphere. Which meant, like her victims, she was also vulnerable.

The computer signaled ready. Vexa assessed her new system configuration. “Chief. Prepare yourself for a slight temporal dilation.”

The chief turned. “I don't know what that means.”

Vexa activated the signal jamming transmissions, this time on a triaxillating band modulated with chronoton phase emissions, aimed back onto the ship itself.

Suddenly everything began to interlace in time, from milliseconds before to milliseconds after the event. Grif studied his hand, trailing back and forth. Sound seemed to rise and fall in echo. Vexa found the effect most...hypnotic.

On the visual uplink to the bridge, the intruder shot up out of her seat to physically inspect the Ops station. When various commands failed to respond, she turned, and cocked her head, mystified, directly at Vexa.

“She didn't plan on you,” Grif said.

“Paris to Vexa. Report.”

“We are currently experiencing the time dilation effect of chronophasic emission interlaced with subspace interferometric frequencies. For now they seem to have blocked the intruder's access to ship systems, Sir.”

“I don't know what you did, but people are starting to wake up. Ship status?”

“Sixty-eight percent of the crew have been transported to Voyager, Sir. Sir, I'm picking up another trellium fusion source.”

“Another actuator?”

“I do not believe this to be the case. Logically, had it been so it would have done its damage by now; but I have ensured that that particular ploy would not succeed twice. It is more likely the generator is being used to power a portable transporter unit. This would explain how the intruder was able to beam herself to the bridge while crew were being displaced to Voyager.”

“Vexa, Seven of Nine is no longer on board. We're depending on you. Can you give us an emergency site to site transport to the main bridge?”

“Affirmative, Sir.”

“When you're ready. Four to beam.”

Chief Grifahni grabbed his phaser rifle. “Us too.”

Sublieutenant Vexa and Chief Grifahni materialized beside her bridge station; the others beamed in interspersed around the upper ring of the main bridge, surrounding the intruder. Lieutenants Bessek and Tiroj fired their phasers. The beams ricocheted off of the intruder, engulfing them and the computer panels behind them. They fell instantly. The intruder paused, and twitched her head.

The next phaser beam hit her from behind. Commander Paris ducked aside as he shot, but his beam seemed to get instantly absorbed by the intruder. She then raised a small device that rippled the atmosphere in a concentrated beam and hit the Commander in the shoulder, sending him reeling into the wall, then forward over the rail and into the pit. He didn't get up.

Lieutenant Munich activated her combadge. “Doctor to bridge immediately! Bring your medkit! And a phaser!” She ran from the body of Lieutenant Commander Tiroj, to Commander Paris.

Grif looked at his rifle, and threw it down. “Find that trellium source, Vexa,” he said, and launched himself over the rail, into the pit. Vexa increased her scans, checking over her shoulder at what was happening. The intruder lithely avoided Grif's flurrying hand strikes and somehow sent him flying across the bridge mercilessly into the far wall.

Vexa's panel pinged.

“Captain, I've located the energy source,” she said. “It's located in the forward torpedo room. A portable transporter!”

Tuvok activated a command from the tactical station, phaser in hand, and turned. A security containment field erupted around the intruder. The intruder stilled, and resumed sitting.

“Can you isolate its programming?”

“Negative, Sir. I'm not even sure it utilizes programming.”

“You've got to block it, Vexa!” Grif strained.

She paused to think. “I am remotely accessing a torpedo matter-antimatter power generator. I believe I can force it to generate an ionic disruption field.” Since the experience with the Cardassian actuator, Vexa had determined twenty-seven alternative methods for neutralizing transporter beams. And now, twenty-eight.

Grif shouted, “Is that safe??”

Vexa continued her work. “Negative. But it will prevent further transport.” She shook her head. “One way or another.”

The containment field began to flicker and spark. The intruder appeared to be glowing.

“Nice job, Vexa.” Grif painfully put his hand on her shoulder. “Now help me get this containment field stabilized.”

Just as he spoke, the containment field fell. The intruder spun and righted herself like an acrobat.

Grif launched himself at her. This time he managed to avoid her counterattack and landed an elbow to her head. She rotated down and right back up again, reversing his attack back onto himself. Vexa gasped when she sent Grif to the wall for a second time.

Suddenly the intruder glowed in the shimmering distortion of her transporter field. Tuvok jumped in with her. They disappeared together in an instant.

Grif complained from the floor. “How did she do that?”

Vexa checked her transporter ionic disruption field. It was still working. “Unknown.”

“Commander Paris,” Munich said. “He's awake.”

Vexa checked her sensor scans. “Sir! The intruder's transport is localizing on Voyager's bridge. She has another transporter unit hidden on Voyager!”

“Put 'em on main viewer!” the commander strained.

The viewer displayed the intruder materializing on the Voyager bridge. She instantly turned – right into Tuvok's mind melding clutch.

Vexa clawed her station. Alarms buzzed on so many interfaces it was impossible to keep them all straight. On her scans, Voyager lay obscured behind indiscernible, dizzying subspace energy reactions. The transporter link started sending crew from Voyager back to the Perseus. Even the intruder's transporter was sending them back – faster than all the transporters of both ships put together.

Commander Paris painfully hauled himself into the Captain's chair. Vexa disabled the chronophasic emitters, and local spacetime rectified. Everyone breathed a sigh of relief – including her. She studied the chaotic systems interface.

On the main viewer, Tuvok locked the intruder in a violent mental embrace.

Suddenly the bridge lights flickered, and the Perseus went to red alert. The computer sounded: “One minute to auto-destruct.”

“Computer, abort auto destruct! Computer! Abort! Damn.” Commander Paris scanned what remained of his bridge crew. “Bridge to Seven of Nine! Seven! Damn!” Commander Paris clutched his bleeding shoulder from his slouching position. “I'm the only senior officer left. Vexa, see if you can shut off the self-destruct!”

Munich studied her panel. “How did she do that?”

Vexa exhaled. “Unknown.”

The intruder's eyes rippled. Captain Tuvok's expression changed. He began to falter.

“Twenty seconds to auto-destruct.”

Commander Paris punched codes into his chair interface, to no avail. “Can you deactivate the auto-destruct Vexa?”

“I...not without the codes, sir!”

The commander's combadge interrupted: Seven of Nine to bridge. My team have been beamed back aboard Perseus.

On screen, Tuvok shook. The intruder began to overpower his mind. She broke his hold and he fell to his knees, wild-eyed, vacant and unmoving. The visual link broke and the screen switched to the external view of Voyager, now completely obscured in blinding subspace eruptions.

The turbolift opened. Ensign Shir and Dr. Salvatore ran into the bridge and rushed to the wounded. The doctor went first to Lieutenant Commander Bessek, then Tiroj. Lieutenant Munich shook her head. “I just received word from the Voyager EMH, Commander,” Salvatore said, studying Tiroj's fatal injuries. “He received a communique from Starfleet five minutes ago.”

Commander Paris stumbled back; Vexa watched the horror cross his face, and did not envy humans.

“Sir!” Ensign Shir shouted. “I'm detecting a slipstream opening up bearing three four three mark twenty-one!”

“What? On main viewer.”

They all turned to the main viewscreen. A quantum vortex erupted off their port bow. Voyager slowly emerged from the subsiding subspace distortion. Vexa returned to her flickering sensor analysis. “Sir, the ship – the ship is equipped with quantum drive modifications.” She faced the viewscreen. “She didn't want Perseus. She wanted Voyager.”

The starship Voyager vectored its nacelles and turned into the slipstream with a blinding flash.

Unmoving, Vexa silently watched Munich and Shir face their commander in defiance. Grif leaned over the railing; “Sir, this is the only ship in the fleet capable of laying in a pursuit, and you know it!”

Commander Paris waved off the doctor and righted his posture. He scanned the faces around him.

Vexa found herself at a complete loss. She thought to herself, The security of Starfleet by far outweighs the consequences to the individual lives aboard that ship and this one. The Commander's purview ends here. Yet she could not seem to convince herself, nor apparently, hide the telling trace of emotion from her face.

His wife and daughter's lives hanging in the balance; along with Starfleet orders, Federation security, and Logic - against the lives of the Voyager crew. Vexa found she could not calculate such a probability. Then suddenly she saw an entirely new emotion flash across the Commander's face.